HDMI output success?

Hi,
I have had success in the output with the LG Rev to my 24" external monitor, but unsuccessful in the output to a Lilliput 7" monitor. I have both DVI and HDMI modes on the Lilliput 7" monitor and it supports resolution from 800 × 480, up to 1920 × 1080 (identical to my 24" monitor) yet NO JOY in seeing the mirror in the 7".
Any ideas?